#include <stdio.h>
#include <stdlib.h>
#include <string.h>

int abs_diff(int a, int b) {
    return a > b ? a - b : b - a;
}

int solution(int* nums, int n) {
    if (n <= 1) return 0;
    
    // Calculate original value
    int originalValue = 0;
    for (int i = 0; i < n - 1; i++) {
        originalValue += abs_diff(nums[i], nums[i + 1]);
    }
    
    int maxValue = originalValue;
    
    // Try all possible reversals
    for (int i = 0; i < n; i++) {
        for (int j = i; j < n; j++) {
            if (i == j) continue; // Single element, no change
            
            // Calculate change in value
            int change = 0;
            
            // Remove old connections
            if (i > 0) {
                change -= abs_diff(nums[i - 1], nums[i]);
            }
            if (j < n - 1) {
                change -= abs_diff(nums[j], nums[j + 1]);
            }
            
            // Add new connections after reversal
            if (i > 0) {
                change += abs_diff(nums[i - 1], nums[j]);
            }
            if (j < n - 1) {
                change += abs_diff(nums[i], nums[j + 1]);
            }
            
            int newValue = originalValue + change;
            if (newValue > maxValue) {
                maxValue = newValue;
            }
        }
    }
    
    return maxValue;
}

int main() {
    char line[10000];
    fgets(line, sizeof(line), stdin);
    
    // Parse JSON array
    int nums[1000];
    int n = 0;
    char* ptr = line + 1; // Skip '['
    while (*ptr && *ptr != ']') {
        if (*ptr >= '0' && *ptr <= '9' || *ptr == '-') {
            nums[n++] = atoi(ptr);
            while (*ptr && *ptr != ',' && *ptr != ']') ptr++;
        }
        if (*ptr == ',') ptr++;
    }
    
    printf("%d\n", solution(nums, n));
    return 0;
}